Sethekk Halls in TBC is one of the dungeons you may find yourself coming back to, depending on which items you are farming.
Sethekk Halls TBC: Which Items are You Farming?
Just as any dungeon, Sethekk Halls is home to some classes pre-raid BiS, items that are the "best in slot" before people enter the first raids of TBC, Gruul's Lair, and Karazhan.
Beast Mastery Hunters would love to farm for Ravenclaw Band, one of the two best rings they can get pre-raid. Balance Druids picking up the Sethekk Oracle Cloak could really use the spell hit, as well as the increase to their healing and magic damage.
If particular pieces of gear is something you're not looking for, Sethekk Halls is one of the better of the four dungeons in Auchindoun to farm Spirit Shards with. Once your faction controls the five Spirit Towers, Sethekk Halls is one of the four dungeons whose bosses drop two Spirit Shards, as opposed to one in Mana-Tombs or Auchenai Crypts.
Sethekk Halls even is home to the coveted mount Reins of the Raven Lord. In order to summon the boss who drops the mount, Anzu, you must enter the dungeon with a Druid on Heroic difficulty. In order to summon Anzu, the Druid must have access to their quest to get their Flight Form, in which a moonstone is given to them. Once the Druid completes the quest initially, they can keep retrying and summon Anzu every time for a chance at the Raven Lord.
A few BiS pieces, Spirit Shards, and one of the most sought after TBC mounts is a few of the most important farmable pieces of content in Sethekk Halls.